Low Blood Pressure Variability Research Articles

624 A Retrospective Review of Blood Pressure Variability (BPV) and Abdominal Aortic Aneurysm (AAA)

Abstract Background Abdominal aortic aneurysms (AAA) rupture risk increases with expansion. Understanding of factors influencing AAA growth are crucial to reduce the risk of rupture. Blood pressure (BP) is considered a contributor to AAA formation, but the association with AAA growth remains unclear. Blood pressure variability (BPV) has emerged as an important cardiovascular risk factor, yet its relationship with AAA growth has not been investigated. Method A retrospective review of 90 patients participating in a multi-centre AAA growth study (NCT05376514) was conducted. Mean growth (mm/yr) was calculated from first and most recent duplex ultrasound scans. Outpatient BP readings between scans were used to calculate BPV defined as the standard deviation (SD) of systolic and diastolic values. Patients were stratified into high and low BPV groups and again into tertiles. Mann-whitney U and unpaired T-tests were used for group comparisons, Kruskall-Wallis to assess for a dose-response relationship between tertiles of BPV. Multiple regression analysis examined variable impact on growth. Results High diastolic BPV was associated with a faster growth rate (2.05 mm/yr [IQR= 1.00 – 3.00]) vs low diastolic BPV (1.44 mm/ yr ([IQR= 0.475-2.00]p=0.036) with a significant dose-response relationship between the lowest and highest BPV tertiles (p= 0.019). DBPV was a significant predictor of AAA growth in the multiple regression model for tertile classification (p=0.016). There was no association between systolic BPV and faster AAA growth rates. Conclusions There was a significant association between higher diastolic blood pressure variability and AAA growth. DBPV may be an important risk stratification tool.

Combined effect of time in target range and variability of systolic blood pressure on cardiovascular outcomes and mortality in patients with hypertension: A prospective cohort study.

Time in target range (TTR) and blood pressure variability (BPV) of systolic blood pressure (SBP) are independent risk factors for major adverse cardiovascular events (MACE) and all-cause mortality in hypertensive patients. However, the association of the combination of low TTR and high BPV of SBP with the risk of MACE and all-cause mortality is unclear. This study sought to investigate the combined effect of the TTR and BPV on the risk of MACE and all-cause mortality in patients with hypertension. A total of 11 496 hypertensive patients from the Kailuan cohort study were included in our study. All participants were divided into four groups according to their TTR and BPV levels. Cox proportional hazards regression models were used to calculate the hazard ratios (HRs) and 95% confidence interval (CI) for incident MACE and all-cause mortality. During a median follow-up of 5.64 years, 839 MACEs (included 99 cases of myocardial infarction, 591 cases of stroke, and 191 cases of heart failure) and 621 deaths occurred. Compared with the high-TTR and low-BPV group, the HRs (95% CI) of MACE and all-cause mortality were 1.309 (1.025-1.671) and 1.842 (1.373-2.473) for the high-TTR and high-BPV group, 1.692 (1.347-2.125) and 1.731 (1.298-2.309) for the low-TTR & low-BPV group, 2.132 (1.728-2.629) and 2.247 (1.722-2.932) for the low-TTR & high-BPV group. Our study suggests that the combination of low TTR and high BPV of SBP was associated with a higher risk of MACE and all-cause mortality in patients with hypertension.

Abstract 51: Impact of Cerebral Autoregulation on the Relationship Between Blood Pressure Variability and Functional Outcome Following Endovascular Thrombectomy

Background: Both increased blood pressure (BP) variability and impaired autoregulation have been linked to worse outcome after endovascular thrombectomy (EVT). This study examined the combined effect of these variables on the risk of poor outcome in patients with large-vessel occlusion (LVO) stroke. Methods: Autoregulation was continuously measured for up to 24 hours after EVT and quantified as a moving correlation coefficient between arterial BP and the near-infrared spectroscopy-derived cerebral oxygen saturation. Systolic BP variability was assessed using the standard deviation of the mean. Values were averaged for the entire recording period and dichotomized at the lowest tertile for both variables. Functional outcome was assessed using the modified Rankin scale (mRS) at 90 days and dichotomized into good (mRS 0-2) and poor outcome (mRS 3-6). Results: We included 195 patients (mean age 70 + 16, 45% female, mean NIHSS 14, mean monitoring time 15 + 7 hours). After adjusting for age, NIHSS, ASPECTS, and TICI score, patients with low BP variability and intact autoregulation were significantly more likely to achieve a good outcome than those with high BP variability and impaired autoregulation (OR 3.7, 95% CI 1.2-12.1, p=0.028, Figure 1A). We found an interaction between BP variability and autoregulation (p=0.067). Patients with high BP variability showed a gradual decrease in the probability of a good outcome with worsening autoregulation. However, for patients with low BPV, autoregulation had minimal impact. (Figure 1B). No significant correlation was seen between autoregulatory function and BP variability (r=0.07, p=0.33). Conclusions: For LVO stroke patients with high BP variability after EVT, worse 90-day functional outcome may be exacerbated by impaired autoregulation. These results suggest that autoregulatory status should be considered in the management of BP after EVT to identify high-risk patients and develop individualized treatment strategies.

The Promise of Cilnidipine in Hypertension with Comorbidities: National Consensus Statement: National Consensus Group Comprises Cardiologists, Nephrologists, and Diabetologists from India in a National Meet at New Delhi held on 22nd May 2022.

The rapidly increasing burden of hypertension is responsible for premature deaths from cardiovascular disease (CVD), renal disease, and stroke, with a tremendous public health and financial burden. Hypertension detection, treatment, and control vary worldwide; it is still low, particularly in low- and middle-income countries (LMICs). High blood pressure (BP) and CVD risk have a strong, linear, and independent association. They contribute to alarming numbers of all-cause and CVD deaths. A major culprit for increased hypertension is sympathetic activity, and further complications of hypertension are heart failure, ischemic heart disease (IHD), stroke, and renal failure. Now, antihypertensive interventions have emerged as a global public health priority to reduce BP-related morbidity and mortality. Calcium channel blockers (CCB) are highly effective vasodilators. and the most common drugs used for managing hypertension and CVD. Cilnidipine, with both L- and N-type calcium channel blocking activity, is a promising 4th generation CCB. It causes vasodilation via L-type calcium channel blockade and inhibits the sympathetic nervous system (SNS) via N-type calcium channel blockade. Cilnidipine, which acts as a dual L/N-type CCB, is linked to a reduced occurrence of pedal edema compared to amlodipine, which solely blocks L-type calcium channels. The antihypertensive properties of cilnidipine are very substantial, with low BP variability and long-acting properties. It is beneficial for hypertensive patients to deal with morning hypertension and for patients with abnormal nocturnal BP due to exaggerated sympathetic nerve activation. Besides its BP-lowering effect, it also exhibits organ protection via sympathetic nerve inhibition and renin-angiotensin-aldosterone system inhibition; it controls heart rate and proteinuria. Reno-protective, neuroprotective, and cardioprotective effects of cilnidipine have been well-documented and demonstrated.

Variability in home blood pressure and its association with renal function and pulse pressure in patients with treated hypertension in primary care

Blood pressure variability (BPV) represents a cardiovascular risk factor, regardless of mean level of blood pressure (BP). In this post-hoc analysis from the PERson-centredness in Hypertension management using Information Technology (PERHIT) study, we aimed to explore BPV in daily home measurements in hypertensive patients from primary care, to identify factors associated with high BPV and to investigate whether estimated glomerular filtration rate (eGFR) and pulse pressure, as markers of target organ damage (TOD), are associated with BPV. For eight consecutive weeks, 454 participants reported their daily BP and heart rate in their mobile phone, along with reports of lifestyle and hypertension-related factors. Systolic BP (SBP) values were used to calculate BPV with coefficient of variation (CV) as primary estimate. Background characteristics and self-reports were tested between fifths of CV in a linear regression model, adjusted for age and sex. Associations between BPV and eGFR and pulse pressure were tested with linear and logistic regression models. Higher home BPV was associated with higher age, BP, heart rate, and smoking. BPV was lower for participants with low alcohol consumption and treatment with calcium channel blockers. There was a significant association between BPV and pulse pressure (P = 0.015), and between BPV and eGFR (P = 0.049). Participants with high BPV reported more dizziness and palpitations. In conclusion, pulse pressure and eGFR were significantly associated with home BPV. Older age, high BP, heart rate, and smoking were associated with high BPV, but treatment with calcium channel blockers and low alcohol consumption was associated with low BPV. Trial registration: The study was registered with ClinicalTrials.gov [NCT03554382].

Left atrial structure and function: association with blood pressure variability in pregnant women.

The aim of this study was to investigate the relationship between left atrial (LA) abnormalities and ambulatory blood pressure variability (BPV) in pregnant women and their relationship with hypertension-related clinical outcomes in pregnancy. This single-center, prospective study included 119 pregnant women. All participants underwent 24-h ambulatory blood pressure (BP) monitoring and echocardiographic examination before 20 weeks of gestation. BPV was evaluated using 24-h ambulatory BP monitoring. SD of the mean of SBP (SBP-SD) and DBP variability was calculated as 24-h, daytime and nighttime SBP and DBP. The patients were classified into two groups based on median 24-h SBP-SD (11.3 mmHg). LA features of the patients were compared according to the high and low BPV groups. One hundred and nineteen pregnant women (mean age, 28.6 ± 5.2 years) were included in the study. The mean office SBP and DBP were 108.7 ± 15.4 mmHg and 68.2 ± 10.2 mmHg, respectively. In pregnant women with high BPV, even though BP is normal, reservoir and conduit LA functions have decreased and LA stiffness has increased. Gestational hypertension and composite outcomes were more common in pregnant women with high BPV. Among the LA parameters, the most associated with composite outcome was conduit LA function. In pregnancy, higher BPV is associated with worse LA function. The LA conduit strain offers potential value in predicting hypertension-related clinical outcomes in pregnancy.

Therapeutic target and clinical impact of day-to-day blood pressure variability in hypertensive patients with covid-19.

Blood pressure variability (BPV) is essential in hypertensive patients and is frequently associated with organ damage. As of today, hypertension is still the most common comorbidity in COVID-19, but the impact of BPV and the therapeutic target of BPV on outcomes in COVID-19 patients with hypertension remain unclear. Therefore, this study investigated the relationship between BPV and severity of COVID-19, in-hospital mortality, hypertensive status, and efficacy of antihypertensives in suppressing hypertensive covid-19 patient BPV. This cohort retrospective study enrolled 351 patients hospitalized with COVID-19. Subjects were classified according to the severity of COVID-19, the presence of hypertension, and their BPV status. During hospitalization, mean arterial pressure (MAP) was measured at 6 a.m. and 6 p.m., and BPV was calculated as the coefficient of variation of MAP (MAPCV). MAPCV values above the median were defined as high BPV. In addition, we compared the hypertensive status, COVID-19 severity, in-hospital mortality, and antihypertensive agents between the BPV groups. The mean age was 53.85 ± 18.84 years old. Hypertension was significantly associated with high BPV with prevalence ratio (PR) = 1.38 (95% CI = 1.13–1.70; p = 0.003) or severe COVID-19 (PR = 1.39; 95% CI = 1.09–1.76; p = 0.005). In laboratory findings, high BPV group had lower Albumin, higher WBC, serum Cr, CRP, and creatinine to albumin ratio. High BPV status also significantly increased risk of mortality (HR = 2.30; 95% CI = 1.73–3.86; p < 0.001). Patients with a combination of severe COVID-19 status, hypertension, and high BPV status had the highest risk of in-hospital mortality (HR = 3.51; 95% CI = 2.32–4.97; p < 0.001) compared to other combination status groups. In COVID-19 patients with hypertension, combination therapy with calcium channel blockers (CCB) as well as CCB monotherapy significantly develop low BPV (PR = 2.002; 95 CI% = 1.33–3.07; p = 0.004) and low mortality (HR = 0.17; 95% CI = 0.05–0.56; p = 0.004). Hypertensive status and severe COVID-19 were significantly associated with high BPV, and these factors increased in-hospital mortality. CCBs might be antihypertensive agents that potentially effectively suppressing BPV and mortality in COVID-19 patients.

Temporal profiles of systolic blood pressure variability and neurologic outcomes after endovascular thrombectomy.

Observational studies have found an increased risk of hemorrhagic transformation and worse functional outcomes in patients with higher systolic blood pressure variability (BPV). However, the time-varying behavior of BPV after endovascular thrombectomy (EVT) and its effects on functional outcome have not been well characterized. We analyzed data from an international cohort of patients with large-vessel occlusion stroke who underwent EVT at 11 centers across North America, Europe, and Asia. Repeated time-stamped blood pressure data were recorded for the first 72 h after thrombectomy. Parameters of BPV were calculated in 12-h epochs using five established methodologies. Systolic BPV trajectories were generated using group-based trajectory modeling, which separates heterogeneous longitudinal data into groups with similar patterns. Of the 2041 patients (age 69 ± 14, 51.4% male, NIHSS 15 ± 7, mean number of BP measurements 50 ± 28) included in our analysis, 1293 (63.4%) had a poor 90-day outcome (mRS ⩾ 3) or a poor discharge outcome (mRS ⩾ 3). We identified three distinct SBP trajectories: low (25%), moderate (64%), and high (11%). Compared to patients with low BPV, those in the highest trajectory group had a significantly greater risk of a poor functional outcome after adjusting for relevant confounders (OR 2.2; 95% CI 1.2-3.9; p = 0.008). In addition, patients with poor outcomes had significantly higher systolic BPV during the epochs that define the first 24 h after EVT (p < 0.001). Acute ischemic stroke patients demonstrate three unique systolic BPV trajectories that differ in their association with functional outcome. Further research is needed to rapidly identify individuals with high-risk BPV trajectories and to develop treatment strategies for targeting high BPV.

ANALYSIS OF AMBULATORY BLOOD PRESSURE MONITORING AND BLOOD PRESSURE MANAGEMENT IN A GERIATRIC REHABILITATION UNIT

Objective: Blood pressure variability (BPV) has proven prognostic importance. Research has shown that controlling BPV in addition to overall reduction of BP in hypertension improves cardiovascular risk. Patients with diagnosed hypertension have an increased association with wider BPVs. Ambulatory blood pressure monitoring (ABPM) is the gold standard in diagnosis of HTN and measuring BPV. We aimed to analyse ABPM data on rehabilitation inpatients and assess hypertension (HTN) management. Design and method: A retrospective analysis of ABPM data of 32 patients sequentially admitted to a geriatric rehabilitation unit in an orthopaedic hospital from Jan 2019 – Jan 2020. We measured the change in medication, quantifying it by escalation and de-escalation (addition/reduction in antihypertensives) or no change if nothing was done. In addition we measured OH. We also analysed BPV by subdividing patients into three groups – High, Medium, and Low daytime BPV based on the standard deviation of daytime SBP. Results: Patient demographics summary (Table 1). There was increased OH detected in the High variability compared to the Low group this had borderline significance (High 75% vs Low 29%, P – 0.06). 37.5% of patients on anti-HTN treatment had an average SBP &gt; 140mmHg. 66.6% of patients with an average SBP &gt; 140mmHg had postural hypotension. 34% of the cohort had OH. 44% of patients with an SBP &gt; 140mmHg had no previous diagnosis of HTN. In this cohort 87% were non night-time dippers. Increased frequency of OH detected in the High variability compared to the Low. (High 75% vs Low 29%, P – 0.06). The High variability also had a significantly higher eGFR when compared to the Low variability (High 88 vs Low 60, P – 0.04) (Table 2). Conclusions: These results show that a significant sub-group of rehabilitation inpatients in our unit had inadequate blood pressure control, underdiagnosed HTN/BPV. This study has shown that ABPM is an effective method for detecting PBV, HTN and sustained night-time HTN in a geriatric rehab population. ABPM should be used as standard of care to detect BPV and OH so that labile BP can be effectively treated and falls risk reduced.

Focus on blood pressure levels and variability in the early phase of acute ischemic stroke with hypertension and carotid stenosis.

To investigate the optimal blood pressure (BP) levels and relative importance of BP and BP variability in the early phase of acute ischemic stroke (AIS) for hypertensive patients with carotid artery stenosis (CAS). A single‐center cohort study included 750 AIS patients with hypertension and tests were performed for CAS. Participants were categorized to Group 1 (SBP < 140 mm Hg and DBP < 90 mm Hg), Group 2: (SBP: 140–159 mm Hg and or DBP: 90–99 mm Hg), and Group 3: (SBP ≥160 mm Hg and/or DBP ≥100 mm Hg) according to the guidelines. The associations of mean BP levels and variability with outcomes (recurrent stroke, all‐cause death and the composite cardiovascular events) at 6 months were analyzed by Cox proportional hazard models. The associations of BP variability with BP levels and cerebral blood flow (CBF) were analyzed by linear regression and generalized additive models. Both for primary and secondary outcome, more events occurred in Group 1 compared with Group 2, while no significant difference was found in Group 3 with higher BP levels. Lower systolic BP variability showed better prognosis and higher CBF. The associations were more significant in patients with CAS ≥50%. BP variability exhibited a linear negative relationship with BP levels. In the early phase of AIS with hypertension and CAS, maintaining low blood pressure variability may be important to improve outcomes while low BP levels (SBP/DBP < 140/90 mm Hg) were harmful, especially in those patients with CAS ≥ 50%.

Impact of in-hospital blood pressure variability on clinical outcomes in patients with symptomatic peripheral arterial disease.

Various types of blood pressure (BP) variability have been recognized as risk factors for future cardiovascular events. However, the prognostic impact of in-hospital BP variability in patients with symptomatic peripheral arterial disease (PAD) has not yet been thoroughly investigated. A total of 386 patients with PAD who underwent endovascular therapy in two hospitals were retrospectively included. BP variability was assessed by the coefficient of variation (CV) of systolic BP measured during hospitalization by trained nurses. The primary endpoint was a composite of major adverse cardiovascular events (cardiovascular death, acute coronary syndrome, stroke, and hospitalization for heart failure) and major adverse limb events (major amputation, acute limb ischemia, and surgical limb revascularization). The mean systolic BP and the CV of systolic BP during hospitalization were 130.8 ± 15.7 mmHg and 11.2 ± 4.1%, respectively. During the median follow-up period of 22 months, 80 patients (21%) reached the primary endpoint. Receiver operating characteristic curve analysis showed that the CV of systolic BP significantly predicted major adverse cardiovascular and limb events (area under the curve 0.60, best cutoff value 9.8, P = 0.01). Using the best cutoff value, patients with high BP variability (n = 242) had a higher risk of clinical events than those with low BP variability (n = 144) (26% vs. 12%, P < 0.001). Multivariable analysis indicated that the CV of systolic BP, age, hemodialysis, and atrial fibrillation were associated with the primary endpoint. In conclusion, greater in-hospital systolic BP variability was associated with major adverse cardiovascular and limb events in patients with symptomatic PAD undergoing endovascular therapy.

PROGNOSTIC IMPORTANCE OF LOW VISIT-TO-VISIT SYSTOLIC BLOOD PRESSURE VARIABILITY IN HIGH-RISK HYPERTENSION

Objective: Besides high blood pressure variability (BPV), low BPV was associated with adverse cardiovascular (CV) prognosis in selected high-risk patients. We explored this issue among high-risk, nondiabetic, nonstroke hypertensive adults from the Systolic Blood Pressure Intervention Trial (SPRINT). Design and method: Long-term SBPV (coefficient of variation, CoV %) was calculated on quarterly visits from randomization until an outcome, excluding titration period and patients with missing visits. The primary outcome was any fatal/nonfatal CV event (myocardial infarction [MI]; acute coronary syndrome not resulting in MI; stroke, acute decompensated heart failure [HF], death from CV diseases [CVD]); secondary outcomes were all-cause mortality and the composite of CV events and mortality. Multivariate (treatment arm, pulse pressure, age &gt; = 75 years, gender, race, CVD, chronic kidney disease [CKD], smoke, n.BP medications) Cox proportional hazard models with penalized smoothing splines were used to explore the potential nonlinear relationship between the continuum of CoV and the HR (95%CI) for outcomes. Sensitivity analysis based on 1:1 propensity score matching (PSM) was performed. Results: The association of SBPV with CV events was J-shaped (lowest risk for CoV 5–10%), while that with all-cause mortality and with the composite outcome was linear. After multivariate adjustment, only low SBPV (CoV &lt; 5%) was associated with CV events (HR 1.85, 95%CI 1.24–2.75), especially MI (HR 2.76, p &lt; 0.001). High SBPV (CoV&gt;10%) was associated with the risk of the composite outcome (HR 1.35, p = 0.037). PSM, matching 566 non-smoker, non-CVD/CKD participants having SBPV 5–10% with an equal number of patients having different SBPV, confirmed the inverse association of low SBPV with CV events (HR 3.33, p = 0.035). Conclusions: Nonlinear modeling indicates that low visit-to-visit SBPV has prognostic relevance in high-risk hypertensives from SPRINT. Unmeasured factors, like inflammatory and metabolic changes, might contribute to the observed results. We treated SBPV as a continuous variable calculated on 16 visits and included 60% of the SPRINT cohort, which might explain the limited analogy with earlier findings. Dedicated trials are needed to test these results and related implications.

Abstract MP33: Association Between Neurologic Outcomes and Temporal Profile of Systolic Blood Pressure Variability After Endovascular Thrombectomy

Introduction: Higher systolic blood pressure variability (BPV) after endovascular thrombectomy (EVT) has been associated with an increased risk of hemorrhagic transformation and worse functional outcomes. However, the time-varying behavior of BPV after EVT and its effects on functional outcome have not been well characterized. Methods: We analyzed data from an international cohort of patients with acute large-vessel occlusion stroke who underwent EVT at 11 centers across North America, Europe, and Asia. Repeated time-stamped blood pressure data were recorded for the first 72 hours after thrombectomy. Parameters of BPV were calculated in 12-hour epochs using five established methodologies: standard deviation (SD), coefficient of variation (CV), average real variability (ARV), successive variation (SV), and residual SD (rSD). Patients’ overall mean BPV was then used to assign patients into tertiles for regression analysis: low BPV, intermediate BPV, and high BPV. Functional outcome was measured with the modified Rankin Scale (mRS) at 90 days. Results: Of the 1,791 patients (age 69 ± 14, NIHSS 15 ± 6) included in our analysis, 1,085 (60.6%) had a poor 90-day outcome (mRS &gt;3). Patients with poor outcome had significantly higher systolic BPV (p&lt;0.05) measured as standard deviation (SBP SD) at each epoch (Figure 1B). Compared to patients with low BPV, those in the highest tertile group had significantly greater odds of a poor functional outcome after adjusting for age, sex, hypertension, NIHSS, ASPECT, tPA, time to reperfusion, and TICI score (OR 1.5; 95% CI 1.2-2; p=0.001). Patients in the highest tertile of BPV demonstrated time-dependent variability with the highest SBP SD during the first 24 hours after thrombectomy (Figure 1A). Conclusions: Higher BPV measured by SBP SD appears to be associated with poor 90-day outcome in EVT-treated stroke patients. Early treatment strategies targeting early high BPV warrant further prospective investigation.

Prognostic importance of long-term SBP variability in high-risk hypertension

In addition to high blood pressure variability (BPV), low BPV was associated with adverse cardiovascular prognosis in selected high-risk patients. We explored this issue in the Systolic Blood Pressure Intervention Trial (SPRINT) using a nonlinear approach with BPV as a continuous variable. Long-term systolic BPV (SBPV) (coefficient of variation, CoV %) was calculated on quarterly visits until a fatal/nonfatal cardiovascular event or all-cause mortality, excluding titration period and patients with missing visits. We used Cox proportional hazard models with penalized smoothing splines to shape the risk of outcomes against the continuum of SBPV (independent variable). Adjusted hazard ratios (aHR, 95% CI) were calculated using the reference range derived from the nonlinear model. Sensitivity analysis based on propensity score matching (PSM) was performed. The association of SBPV with fatal/nonfatal cardiovascular events was J-shaped, whereas that with all-cause mortality was linear. After multivariate adjustment, however, the only significant associations remained that of low SBPV (CoV <5%) with cardiovascular events (hazard ratio 1.85, 95% CI 1.24-2.75, P = 0.003), and of high SBPV (CoV >10%) with the composite of cardiovascular events and all-cause mortality (hazard ratio 1.35, 95% CI 1.02-1.80; P = 0.037). Low SBPV was associated with ischemic heart disease (hazard ratio 2.76, 95% CI 1.55-4.91; P < 0.001). There was a significant U-shaped association of SBPV with cardiovascular events in the PSM cohort. Nonlinear modeling indicates that low and high long-term SBPV have prognostic relevance in high-risk hypertensive individuals from SPRINT. Randomized trials are needed to test these findings and their potential therapeutic implications.

Machine Learning Clustering for Blood Pressure Variability Applied to Systolic Blood Pressure Intervention Trial (SPRINT) and the Hong Kong Community Cohort.

Visit-to-visit blood pressure variability (BPV) has been shown to be a predictor of cardiovascular disease. We aimed to classify the BPV levels using different machine learning algorithms. Visit-to-visit blood pressure readings were extracted from the SPRINT study in the United States and eHealth cohort in Hong Kong (HK cohort). Patients were clustered into low, medium, and high BPV levels with the traditional quantile clustering and 5 machine learning algorithms including K-means. Clustering methods were assessed by Stability Index. Similarities were assessed by Davies-Bouldin Index and Silhouette Index. Cox proportional hazard regression models were fitted to compare the risk of myocardial infarction, stroke, and heart failure. A total of 8133 participants had average blood pressure measurement 14.7 times in 3.28 years in SPRINT and 1094 participants who had average blood pressure measurement 165.4 times in 1.37 years in HK cohort. Quantile clustering assigned one-third participants as high BPV level, but machine learning methods only assigned 10% to 27%. Quantile clustering is the most stable method (stability index: 0.982 in the SPRINT and 0.948 in the HK cohort) with some levels of clustering similarities (Davies-Bouldin Index: 0.752 and 0.764, respectively). K-means clustering is the most stable across the machine learning algorithms (stability index: 0.975 and 0.911, respectively) with the lowest clustering similarities (Davies-Bouldin Index: 0.653 and 0.680, respectively). One out of 7 in the population was classified with high BPV level, who showed to have higher risk of stroke and heart failure. Machine learning methods can improve BPV classification for better prediction of cardiovascular diseases.

Impact of high blood pressure variability on the occurrence of acute type B aortic dissection.

Acute type B aortic dissection is a life-threatening medical emergency, and hypertension is believed to be an important predictor of aortic dissection; the impact of blood pressure variability on the onset and development of aortic dissection has attracted increasing attention. A total of 120 acute type B aortic dissection patients and 57 hypertensive patients without aortic dissection were consecutively enrolled and retrospectively reviewed between January 2013 and November 2015. There were 60 acute type B aortic dissection patients in both high and low blood pressure variability groups. Blood pressure variability showed higher diagnostic value than hypertension in aortic dissection, and the best threshold of blood pressure variability is 5.71 mmHg. By performing multivariable logistic regression, we found that the history of hypertension was likely to be a risk factor of blood pressure variability (95% CI: 1.155-6.422, P = 0.022). Nine patients from high blood pressure variability group and two from low blood pressure variability group (χ2 = 4.90, P = 0.027) received emergency surgery within 24 hours after admission. The presence of multiple tears (>2, 55.0% vs. 45.0%, P = 0.001), configuration of the false lumen (spiral false lumen) (50.0% vs. 21.7%, P = 0.001), the diameter of the false lumen (49.6 ± 15.0 mm vs. 37.6 ± 10.8 mm, P < 0.001), the false/true lumen ratio (1.53 ± 1.02 vs. 0.929 ± 0.733, P < 0.001), and the number of visceral arteries involved (1.75 ± 0.942 vs. 0.800 ± 0.927, P < 0.001) showed significant differences between high and low blood pressure variability groups. Nine (30%) patients from the high blood pressure variability group showed a maximum diameter of false lumen over 60 mm, while none was found in the low blood pressure variability group. High blood pressure variability, the presence of multiple tears (>2), the configuration of false lumen, the diameter of the false lumen, false/true lumen ratio, and the number of visceral arteries involved were independent risk factors for acute type B aortic dissection.

Abstract TMP89: Impaired Cerebral Autoregulation Increases Risk of Worse Outcome After Endovascular Thrombectomy in Stroke Patients With High Blood Pressure Variability

Introduction: Both increased blood pressure (BP) variability and impaired autoregulation have been associated with increased risk of poor outcome after endovascular thrombectomy (EVT). The combined effect of these two variables, however, has not yet been elucidated. We hypothesized that the detrimental effects of high BP variability may be amplified by impaired autoregulation. Methods: We prospectively enrolled patients with large-vessel occlusion (LVO) stroke undergoing EVT. Autoregulatory function was continuously measured for up to 48 hours post-EVT by interrogating changes in near-infrared spectroscopy-derived tissue oxygenation (a cerebral blood flow surrogate) in response to changes in BP (Fig. 1A). BP variability was assessed using the standard deviation of the mean. Values were averaged for the entire recording period and dichotomized based on the median. Functional outcome was assessed using the modified Rankin scale (mRS) at 90 days. We examined the association between BP variability, autoregulatory function, and outcome using ordinal logistic regression, adjusting for age and admission NIHSS. Results: Ninety-five patients (mean age 71, NIHSS 14, monitoring time 28±18 hours) were included. BP variability (p=0.043) and autoregulation (p=0.04) were each independently associated with functional outcome. Among patients with high BP variability, worse autoregulation was independently associated with higher (worse) mRS scores at 90 days (OR 3.9, 95% CI 1.1-14.5, p=0.036; Fig. 1B). The proportion of favorable outcome was highest among patients with low BP variability and better autoregulation, and lowest among those with high BP variability and worse autoregulation (p=0.073; Fig. 1C). Conclusion: For LVO stroke patients with high BP variability after EVT, worse functional outcome may be exacerbated by impaired autoregulation. These results suggest that autoregulatory status should be considered in the management of BP after EVT.

Change in Blood Pressure Variability Among Treated Elderly Hypertensive Patients and Its Association With Mortality.

BackgroundInformation is scarce regarding effects of antihypertensive medication on blood pressure variability (BPV) and associated clinical outcomes. We examined whether antihypertensive treatment changes BPV over time and whether such change (decline or increase) has any association with long‐term mortality in an elderly hypertensive population.Methods and ResultsWe used data from a subset of participants in the Second Australian National Blood Pressure study (n=496) aged ≥65 years who had 24‐hour ambulatory blood pressure recordings at study entry (baseline) and then after a median of 2 years while on treatment (follow‐up). Weighted day‐night systolic BPV was calculated for both baseline and follow‐up as a weighted mean of daytime and nighttime blood pressure standard deviations. The annual rate of change in BPV over time was calculated from these BPV estimates. Furthermore, we classified both BPV estimates as high and low based on the baseline median BPV value and then classified BPV changes into stable: low BPV, stable: high BPV, decline: high to low, and increase: low to high. We observed an annual decline (mean±SD: −0.37±1.95; 95% CI, −0.54 to −0.19; P<0.001) in weighted day‐night systolic BPV between baseline and follow‐up. Having constant stable: high BPV was associated with an increase in all‐cause mortality (hazard ratio: 3.03; 95% CI, 1.67–5.52) and cardiovascular mortality (hazard ratio: 3.70; 95% CI, 1.62–8.47) in relation to the stable: low BPV group over a median 8.6 years after the follow‐up ambulatory blood pressure monitoring. Similarly, higher risk was observed in the decline: high to low group.ConclusionsOur results demonstrate that in elderly hypertensive patients, average BPV declined over 2 years of follow‐up after initiation of antihypertensive therapy, and having higher BPV (regardless of any change) was associated with increased long‐term mortality.

A relationship of intradialytic blood pressure variability with vascular access outcomes in patients on hemodialysis.

Vascular access dysfunction is a major cause of morbidity in patients with end-stage renal disease (ESRD) on hemodialysis (HD). Thus, identifying risk factors for vascular access failure is important. Patients on HD are routinely exposed to high blood pressure variability (BPV) during HD. However, the impact of intradialytic BPV on vascular access outcomes is unknown. Therefore, we investigated the association of intradialytic BPV with vascular access outcomes in patients on HD. One hundred and thirty patients with ESRD who created vascular access for HD were evaluated. We examined 12 dialysis sessions per patient and recorded BP five times for each session. BPV was assessed using residual standard deviation derived from the linear regression model. The patients were divided into two groups according to a level below or above the median value of intradialytic BPV and compared. The primary outcome was primary unassisted vascular access patency. The median time to loss of primary unassisted patency was significantly longer in low intradialytic BPV group than in high intradialytic BPV group (52 months vs. 21 months, P < 0.001) during the mean follow-up of 3.7 years. After adjustment for other variables, high intradialytic BPV was significantly associated with loss of primary unassisted vascular access patency (hazard ratio, 2.605; 95% confidence interval, 1.462-4.643; P = 0.001). Our study revealed a significant correlation between intradialytic BPV and vascular access patency. Further studies are needed to identify methods for lowering BPV.

A13842 Blood pressure variability was associated with Cystatin c level in Acute Hemorrhage Stroke

Objectives: Cystatin c (Cys c) is a good indicator in early renal dysfunction. Blood pressure variability (BPV) is closely related to target organ damage, especially the kidney. We aimed to explore Cys c level and the relationship with BPV in hemorrhage strokes. Methods: A total of 141 first-ever hemorrhage stroke cases were recruited in our study. Cys c, blood uric acid, blood creatinine were determinate and 24-hours ambulatory blood pressure for the first 7 consecutive days (7-day/24-hours) were monitored. Standard deviation was used to describe the BPV. Patients were divided into low BPV group (L-BPV) and high BPV group (H-BPV) according to the median of the 7-day/24-hours BPV. Described methods, univariateanalysis and multiple linear regressions were used for analysis. Results: The concentration of Cys c in H-BPV group (1.01 ± 0.38 mg/L) was higher than that in L-BPV group (0.85 ± 0.41 mg/L), (t = 2.35, P = 0.02). The 7-day/24-hours BPV of systolic blood pressure (SBP) in H-BPV group (17.21 ± 2.76)was higher than that of L-BPV group (11.14 ± 1.78), (t = 15.47, P = 0.001). The 7-days SBP BPV was positively correlated with Cys c level (r = 0.34, P = 0.001). Multiple linear regression analysis showed that 7-days/24-hours SBP BPV, serum creatinine, blood uric acid, gender and age were the main influencing factors of cys c level (all P < 0.05). Conclusion: BPV was the important influencing factors for Cystatin c level and may be an useful indicator for early renal dysfunction in acute hemorrhage stroke.